1. Fit To Screen
There should be a minimum scroll, zooming-in and out involved in an application. A mobile screen should accommodate all the content to the available size as far as possible.

2. Typography
It involves font size, font style, font color and other details to be manipulated. Size of the font matters when it has to be readable by users.

3. Use of Emulators For Testing
emulators are available for testing the apps for all kinds of devices with different sizes.

4. User Interaction In 3D Touch
3D Touch adds an additional dimension to touch-based interaction. On supported devices, people can access additional functionality by applying varying levels of pressure to the touchscreen.

5. Error/Exception Handling Techniques
Exceptions are caused by programming faults and must be fixed or handled. Errors are expected to happen from time to time and should be dealt with.

6. Create A Directory Structure
It is always a rule of thumb to create a hierarchy of project files which will show up different levels for file systems you are working with. Without intuitive project structure, your code can get messy and unorganized.

Managing iOS projects are not the tough tasks when followed the above guidelines.